Search results for " control system"
showing 10 items of 262 documents
Architecture of a digital PFM controller for IC implementation
2006
This paper presents a digital controller architecture oriented to IC implementation. The classical digital pulse width modulator (D-PWM), using digital analog converter (DAC), is replaced with a Sigma-Delta (/spl Sigma//spl Delta/) modulator based on pulse frequency modulator (PFM) technique. Results of an investigation from a prototype for DC-DC converter, in terms of simulated and experimental performances, are reported, together with harmonic frequency investigation. The control function design is implemented on a field programmable gate array (FPGA). As a consequence of good agreement between simulated and experimental results, the proposed architecture realizes a digital control loop w…
Special Issue “Smart Urban Lighting Systems”
2020
The design and operation of multifunctional infrastructures for public lighting as well as their impact on the urban environment and citizens’ life is today of great interest. The cost of energy for public lighting is often an issue for the budget of municipalities. Furthermore, researchers’ and designers’ attention is increasingly focused on aspects of public lighting not directly valuable through economic factors. Starting from the “quality” of the light environment, looking at citizens’ visual comfort, the light has to be considered as an instrument to improve the urban context and objects therein (including buildings). Indeed, urban degradation (lack of infrastructures, maintenance, ser…
Observer-Based ${H}_{\infty }$ Control Design for Nonlinear Networked Control Systems with Limited Information
2013
Published version of an article in the journal: Abstract and Applied Analysis. Also available from the publisher at: http://dx.doi.org/10.1155/2013/604249 Open Access This paper is concerned with the problem of designing a robust observer-based H∞ controller for discrete-time networked systems with limited information. An improved networked control system model is proposed and the effects of random packet dropout, time-varying delay, and quantization are considered simultaneously. Based on the obtained model, a stability criterion is developed by constructing an appropriate Lyapunov-Krasovskii functional and sufficient conditions for the existence of a dynamic quantized output feedback cont…
Control systems for indoor lighting and computer simulation: analysis and comparison between software packages capabilities and results on a real cas…
2018
In the last years, computer capabilities have evolved rapidly and also the way to simulate building physics phenomena is changed and more developed. Each simulation software is developed with a less or more similar aim, using different algorithms and models and being used by people with different profile: specialist, architects, engineers, installers, etc. This paper deals with the analysis of capability of some of the most utilised software used to predict indoor lighting, including natural daylight contribution and assessment of energy consumption and savings related to specific design options. Furthermore, two of the analysed software have been tested simulating a case studying. Results …
Effects of Client Pressure and Audit Firm Management Control Systems on Auditor Judgments
2015
We examine the effects of pressures from client management and the audit firm’s own management control systems (MCS) on auditors’ willingness to accept an aggressive accounting that is preferred by client management. We find that auditors perceiving more pressure from client management to accept the client’s aggressive accounting react by increasing the size of the proposed adjustment needed to bring the client’s accounting into conformity with GAAP. However, we find that when client management promotes the jointness of interests they share with the auditor or the audit firm’s MCS focuses the auditor more on client service quality the auditor experiences increased affinity for the client an…
A New Kinematic and Dynamic Direct Adaptive Fuzzy Control of Constrained Mobile Wheeled Vehicles
2005
In this paper a new kinematic and dynamic adaptive Fuzzy control is applied to a trajectory tracking problem of a constrained vehicle with two indipendent wheels. The vehicle dynamics and kinematics are completely unknown. A dynamical and kinematical adaptive control provide to on line estimation of the dynamic and kinematic parameters of the vehicle model. Moreover the parameters of the kinematic control law are obtained using a Fuzzy controller and they are time varying and dependent on tracking errors. The stabililty of the kinematic and dynamic adaptive Fuzzy control system and the convergence of tracking errors to zero are proved using Lyapunov's method and Barbalat's Lemma. The effect…
Enhancing performance management and sustainable organizational growth through system-dynamics modelling
2012
Organizational growth and performance management provide two important research topics for both enterprises and public sector organizations. Improving performance levels, or at least keeping them stable over time, is a hot topic not only for business executives and entrepreneurs, but also for managers and policy makers in public and non-profit institutions. How best to design Planning & Control (P&C) systems to support organizational performance management and assessment in a sustainability perspective? This paper illustrates the need for a methodological framework that would link system dynamics to P&C systems so as to support decision-makers in managing organizational performance, as well…
Beyond budgeting since inception: what is the status?
2017
Master's thesis Business Administration BE501 - University of Agder 2017 The Beyond Budgeting idea as developed by Hope and Fraser (1997) has been in existence for almost twenty years, yet, the research community still has divergent views on whether the concept is a better management accounting tool for organizations’ management control system or not. Also, whether it has received attention in research community like other management accounting tools such as Traditional Budgeting and Balanced Scorecard. On this notion, this study is developed to investigate the status of the research discourse on the concept to gain relevant knowledge. Inspired by Scapens and Bromwich (2001) and built on Ac…
Adaptive Fuzzy Control of a Process with Bifurcations
2002
Several fuzzy controllers with different structures have been considered for the control of systems with bifurcation. A mixed feedforward-feedback structure with some additional adaptation mechanisms have been checked by simulation in the control of a non-linear process constituted by a bubble column in which a slow kinetics auto-catalytic reaction takes place. Simulation results show the validity of some of the proposed controllers in avoiding the system reaching bifurcation and instability conditions.
El efecto mediador y moderador de la internacionalización en la relación entre los sistemas de control de gestión y el compromiso con la innovación
2019
La literatura contable revela resultados contradictorios al evaluar el efecto que los diferentes usos de los sistemas de control de gestión (SCG) tienen en la innovación. Siguiendo el marco teórico establecido por Simons (1995), este trabajo prueba el efecto que la internacionalización, bien sea directo, mediador o moderador, tiene en la relación entre el uso interactivo de los SCG y el compromiso de las empresas con la innovación. Tomando una muestra de 231 organizaciones del sector agroalimentario español, los resultados obtenidos ponen de manifiesto la ausencia de una relación directa entre el uso interactivo del conjunto de herramientas de SCG y el compromiso con la innovación. Del mism…